Abstract

Cerebrovascular amyloid beta-protein (ABeta) deposition is a hallmark of Alzheimer's disease (AD) and related disorders including hereditary cerebral hemorrhage with amyloidosis Dutch-type (HCHWA-D). Cerebrovascular ABeta deposition in these disorders is prominently associated with smooth muscle cellular pathology in the cerebral vessel wall and can lead to a loss of vessel integrity and hemorrhagic stroke. The reasons for this remain unclear. The overall hypothesis that forms the basis of this competing continuation grant proposal is that ABeta deposition in the cerebral vessel wall can modulate the function of hemostatic enzymes thus creating a microenvironment that is conducive to hemorrhagic stroke. The objectives of this proposal are to characterize the effects of ABeta on the regulation of certain hemostatic enzymes at the biochemical and cellular levels.
The specific aims of this proposal are as follows: First, the effect of soluble ABeta, solution-assembled fibrillar ABeta, and cell-surface-assembled, fibrillar ABeta on the inhibition of factor XIa (FXIa) and certain other coagulation enzymes by PN-2/AbetaPP will be characterized. The inactivation rates of FXIa and other coagulation enzymes by PN-2/AbetaPP in the presence of soluble and the different fibrillar ABeta peptides will be determined. The proteolysis of ABeta peptides by coagulation enzymes will be investigated. Second, studies will be conducted to determine the effect of soluble ABeta, solution-assembled fibrillar Abeta, and cell-surface-assembled fibrillar ABeta on the stimulation of tissue plasminogen activator (tPA) activity. The effect of ABeta peptides on cellular tPA levels and plasminogen activation activity will be explored. In addition, proteolysis of ABeta peptides by tPA and plasmin will be investigated. Third, investigations will compare the pathologic effects of intact ABeta and hemostatic enzyme proteolyzed ABeta on cultured human cerebrovascular smooth muscle (HCSM) cells, a cell type intimately associated with the cerebrovascular pathology of AD and HCHWA-D. The proposed studies will provide a better biochemical understanding of the influence that ABeta has on the inhibition of certain coagulation proteases and the stimulation of plasminogen activation, two processes that together can create a milieu which could result in loss of vessel integrity and hemorrhagic stroke.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL049566-07
Application #
6043796
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1992-09-30
Project End
2002-07-31
Budget Start
1999-08-01
Budget End
2000-07-31
Support Year
7
Fiscal Year
1999
Total Cost
Indirect Cost

  Institution

Name
State University New York Stony Brook
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794

  Publications

Jung, Sonia S; Zhang, Weibing; Van Nostrand, William E (2003) Pathogenic A beta induces the expression and activation of matrix metalloproteinase-2 in human cerebrovascular smooth muscle cells. J Neurochem 85:1208-15
Davis, Judianne; Wagner, Matthew R; Zhang, Weibing et al. (2003) Amyloid beta-protein stimulates the expression of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in human cerebrovascular smooth muscle cells. J Biol Chem 278:19054-61
Van Nostrand, William E; Melchor, Jerry P; Keane, David M et al. (2002) Localization of a fibrillar amyloid beta-protein binding domain on its precursor. J Biol Chem 277:36392-8
Wagner, M R; Keane, D M; Melchor, J P et al. (2000) Fibrillar amyloid beta-protein binds protease nexin-2/amyloid beta-protein precursor: stimulation of its inhibition of coagulation factor XIa. Biochemistry 39:7420-7
Mahdi, F; Rehemtulla, A; Van Nostrand, W E et al. (2000) Protease nexin-2/Amyloid beta-protein precursor regulates factor VIIa and the factor VIIa-tissue factor complex. Thromb Res 99:267-76
Van Nostrand, W E; Melchor, J; Wagner, M et al. (2000) Cerebrovascular smooth muscle cell surface fibrillar A beta. Alteration of the proteolytic environment in the cerebral vessel wall. Ann N Y Acad Sci 903:89-96
Hook, V Y; Sei, C; Yasothornsrikul, S et al. (1999) The kunitz protease inhibitor form of the amyloid precursor protein (KPI/APP) inhibits the proneuropeptide processing enzyme prohormone thiol protease (PTP). Colocalization of KPI/APP and PTP in secretory vesicles. J Biol Chem 274:3165-72
Annich, G; White, T; Damm, D et al. (1999) Recombinant Kunitz protease inhibitory domain of the amyloid beta-protein precursor as an anticoagulant in venovenous extracorporeal circulation in rabbits. Thromb Haemost 82:1474-81
Van Nostrand, W E; Porter, M (1999) Plasmin cleavage of the amyloid beta-protein: alteration of secondary structure and stimulation of tissue plasminogen activator activity. Biochemistry 38:11570-6
Van Nostrand, W E; Melchor, J P; Ruffini, L (1998) Pathologic amyloid beta-protein cell surface fibril assembly on cultured human cerebrovascular smooth muscle cells. J Neurochem 70:216-23

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